Kienzler JL, Magnette J, Queille-Roussel C, Sanchez-Ponton A, Ortonne JP

Novartis Consumer Health, Nyon, Switzerland.

The potential of a diclofenac-Na Emulgel (diclofenac gel) to alleviate the pain and associated symptoms caused by sunburn has been evaluated versus vehicle. Sunburn was induced on the buttock skin of healthy adult male subjects by irradiation with UVA + UVB rays. Investigational products were applied 6 and 10 h after irradiation, and efficacy was assessed on the basis of spontaneous and provoked pain, erythema, oedema, skin colour and temperature. The minimal efficacious concentration evaluated in an extension (0.1 vs. 0.25% diclofenac gel) of a previous concentration-finding study (1, 0.5 and 0.25% diclofenac gel) was 0.1% and was efficacious in alleviating pain (spontaneous and provoked) as well as reducing erythema, oedema and skin temperature. In a single- versus 2-application comparison study, a single application of 0.1% gel was sufficient to alleviate the pain and accompanying symptoms of sunburn with an onset of action 2 h after application. A second application of gel 4 h after the first maintained the analgesia and reduction of other symptoms for a period of up to 48 h after irradiation.